code: def validate(style, value, scalar=False):
      """
      Validates a style and associated value.
  
      Arguments
      ---------
      style: str
         The style to validate (e.g. 'color', 'size' or 'marker')
      value:
         The style value to validate
      scalar: bool
  
      Returns
      -------
      valid: boolean or None
         If validation is supported returns boolean, otherwise None
      """
      validator = get_validator(style)
      if validator is None:
          return None
      if isinstance(value, arraylike_types + (list,)):
          if scalar:
              return False
          return all(validator(v) for v in value)
      return validator(value)
  
file_path: holoviews/holoviews/plotting/bokeh/styles.py
imports: import numpy
  from bokeh.core.properties import Angle, Color, DashPattern, FontSize, MarkerType, Percent, Size
  from ...core.options import abbreviated_exception
  from ...core.util import arraylike_types
  from ...util.transform import dim
  from ..util import COLOR_ALIASES, RGB_HEX_REGEX, rgb2hex
label_desc: Use image node_id 3 for calling a global function with example usage: validate(style, value, scalar) and returns: validator, None, all, False